CAD files are the lifeblood engineering organizations run on, but paying for CAD licenses for every user wastes organizations' resources. Workarounds like exporting CAD files into PDFs lead to artifacts and versions that create confusion when looking for a source of truth. 

Engineering document management systems with CAD viewers can supplement your team with CAD accessibility without unnecessary licenses and multiple PDFs showing the project at different stages, or missing important markup information.

What is a CAD File? (Common Formats Explained)

CAD files (short for Computer-Aided Design) are digital documents depicting precise 2D drawings or 3D models. They are used to design, analyze, and manufacture physical objects and structures.

Unlike standard images or PDFs, CAD files store geometry data, dimensions, layers, material properties, and metadata. Downstream teams rely on the information contained in the CAD files to do their jobs accurately.

Depending on the software platform and project type, CAD files come in several formats. Some of the most common:

DWG (.dwg) - Short for drawing; the native file format for Autodesk products like AutoCAD and AutoCAD LT. The vast majority of 2D drafting and design work across AEC (architecture, engineering, and construction) and manufacturing is stored and shared in DWG format.

DXF (.dxf) - Acronym for Drawing Exchange Format; introduced by Autodesk in 1982 as an open, vendor-neutral format, DXF was purpose-built to allow 2D and 3D CAD designs to be shared across different programs and platforms. It’s widely used as an interoperability format when teams are working across different CAD tools.

DGN (.dgn) - Short for design; the proprietary 2D/3D CAD file format native to Bentley Systems’ MicroStation software. DGN is common in large-scale infrastructure, transportation, and civil engineering projects, particularly in government and public works environments.

ASM (.sldasm) – Short for assembly, the proprietary 2D/3D CAD file format native to SolidWorks.  ASMs are also associated to .sldprt files representing parts associated with the assembly.  SolidWorks is common in manufacturing, transportation, and aviation projects where systems, assemblies, and materials are modeled.

External references (or Xrefs) add another layer of complexity to sharing CAD files. They are rarely self-contained.

A single drawing can often reference dozens of external files (base maps, title blocks, detail sheets, manufacturer data). Opening the original CAD file doesn’t work without the reference files.

Send a DWG file without its Xrefs, and the recipient gets an incomplete, often broken file. This dependency structure is one of the core reasons CAD file sharing requires more than a standard file transfer solution.

How to Open a CAD File (without a Full CAD License)

Drawings don’t stop at designers. Project managers, clients, contractors, procurement teams, and executives all regularly need to review CAD files.

Purchasing a full CAD authoring license for every stakeholder isn’t practical or cost-effective.

CAD Viewer vs. CAD Authoring Tool

A CAD authoring tool (like AutoCAD, MicroStation, or SolidWorks) is full-featured software built for creating, editing, and annotating CAD files. These are powerful, expensive, and require significant training to be used effectively.

A CAD viewer, by contrast, is a lightweight application built solely for opening, inspecting, and in some cases marking up CAD files. Viewers don’t allow editing of the underlying geometry.  They give non-technical stakeholders the ability to review drawings, check dimensions, and provide feedback.

Reliable CAD Viewers for Windows, Mac, and Chromebook

The right viewer depends on your operating system, your access to the original file, and whether you want to download the viewing software. Here’s a quick breakdown of the most common approaches:

Desktop Applications offer the most reliable performance for large, complex DWF files with multiple Xrefs. They’re installed locally, work offline, and tend to handle file dependencies more gracefully than browser tools. The tradeoff is that they’re platform-specific, require installation, occasional updates, and needing the file to be local.

DWG TrueView (Windows only) is Autodesk’s free desktop DWG viewer. It opens native DWG and DXF files reliably and includes a batch converter for translating between DWG format versions. While the viewer itself is free, an Autodesk account is required to download and use it.

Browser-Based/ Cloud Viewers eliminate the installation barrier and can work across operating systems. They can be practical for distributed teams and stakeholders using Macs or Chromebooks where native DWG support is limited.

Autodesk Viewer (browser-based) free online viewer that supports DWG, DXF, and several other formats directly in the browser. It requires an Autodesk account and a subscription for access to advanced features, but basic viewing is available at no cost. Useful for quick reviews, though performance can vary with large or Xref-heavy files.

An EDMS with Integrated Viewing is worth calling out as a separate category. An Engineering Document Management System (EDMS) stores your files but can embed CAD viewing into the software.

ImageSite and EngineBox, eQuorum’s EDMS solutions, combine the best of both worlds. As browser-based EDMS, users don’t need to have any software or file installed locally. With a network connection, a link, and permissions, any device can view a CAD file.

How to Convert DWG to PDF (and Why It Matters for Distribution)

The process of converting a .dwg to a PDF changes based on which CAD platform you’re using. If you’re using AutoCAD, you can click application in the top left corner and choose export > pdf. Alternatively, you can press ctrl + p to open the plot dialog and under Printer/Plotter, select DWG to PDF.

When in other CAD authoring tools, the export, print/ plotting, and equivalent options will offer options to convert your CAD file into a PDF.

PDFs make CAD sharing simpler. PDFs are universally readable; no CAD software, no viewer license, no compatibility questions. Anyone on the project can open a PDF from almost any device and see the drawing.

PDFs offer control without software support. While DWG files are editable, PDFs lock the drawing to a static snapshot. For regulated industries where document integrity is a compliance requirement, issuing PDFs rather than native CAD files adds a layer of protection against unauthorized modifications.

PDFs are easier to archive and share at scale. Native CAD files require packaging to ensure all dependent files travel together. A PDF collapses that complexity into a single, self-contained file– making it easy to send as an email attachment. Both ImageSite and EngineBox provide PDF conversion upon upload or on-the-fly during download or publishing.

CAD File Sharing: The Right Way vs. The Wrong Way

The same simplicity that makes PDF a convenient sharing format also makes it a liability. When you convert a CAD file to PDF, you lose everything that makes the source file intelligent: layers, object data, metadata, and editable geometry are stripped out. What remains is just a static image of the drawing.

The version control problem is just as significant. Because PDF conversion is typically a manual step, the PDF circulating in a shared folder or email thread can easily fall out of sync with the CAD file where it came from. It stays where it was without indication something has changed. In multi-discipline project environments, a stale PDF is a quiet source of rework, coordination errors, and costly misalignment that often goes undetected until the damage is done.

For any recipient who needs to do more than review a drawing, a PDF is a dead end. Contractors and partner firms who need to bring your design into their own CAD environment are forced to either manually redraw the geometry or rely on PDF-to-CAD conversion tools, introducing time, cost, and transcription risk.

eQuorum’s ImageSite and EngineBox offer a smarter middle ground. Rather than distributing a static exported PDF, the system streams a PDF directly from the native CAD file stored in the platform. That means any time a file is updated and checked back in, the streamed PDF reflects the current version automatically.

The PDF is streamed from within the platform rather than exported and distributed, the file never leaves the system. There’s no loose copy sitting in someone’s downloads folder, no version forwarded to an unauthorized recipient, and no way for a drawing to walk off the project without a trace. Every interaction with the file (from check-in and version creation to simply opening the drawing for review) is logged and auditable. A level of accountability impossible to enforce once a file hits an inbox.

The streamed PDF living in the EDMS enables collaborative review. Stakeholders markup the streamed PDF directly inside the platform, adding redlines, comments, and annotations without touching the native CAD file.

Those markups are live and visible to the permissioned users in real time. Access controls and audit trails maintain accountability throughout a project’s lifecycle, including markups. Review cycles stay organized and feedback remains tied to the correct document version, rather than scattered across email chains and printed sheets.

Shop Floor Access to CAD Drawings

Printed drawings on the shop floor have one thing in common: they’re out of date the moment something changes. Operators, machinists, and field staff working from last month’s prints aren’t just inefficient – they’re a quality risk. 

Version-controlled access at the point of use solve this. When the drawing in the system is the drawing on the floor, there’s no gap between what engineering issued and what production is building to. 

eQuorum’s ScanNTap module makes this practical without adding complexity. QR codes are tied directly to the controlled document in the system. Any team member with a phone, tablet, or laptop can scan the code and pull up the current, approved drawing in their browser. They don’t need to install an app or hunt through a shared drive. The file they see is always the latest checked-in version. 

Access controls keep the workflow clean. Field staff and operators can be set to read-only or markup-only access, ensuring they can review and flag issues without the ability to modify the source file. Administrators control permissions at the link level, so the right people always have the right access and nothing more.

CAD Stage Progression – Tracking Files From Design to Release

Every CAD drawing moves through a defined lifecycle — from the first draft to the filed archive. Without a system tracking that progression, drawings get used at the wrong stage, approvals get skipped, and superseded versions stay in circulation long after they should have been retired. 

Control and accountability throughout that lifecycle isn't just good practice; it protects your organization's IP and keeps you aligned with compliance standards like ISO 9001.

Here’s what each stage represents and why it matters:

Design is the active authoring stage. A designer creates or modifies a drawing in a CAD authoring tool. Access should be restricted to the engineers working the file, with check-out controls preventing simultaneous edits. 

Review is when the drawing leaves the designer’s hands for technical scrutiny. Peers, leads, or cross-discipline teams evaluate the drawing for accuracy, completeness, and compliance before it can advance. This stage is where markup and redline tools earn their keep. 

Approval is the formal sign-off stage. A designated approver (often a project engineer, department lead, or quality manager) validates that the drawing meets all requirements and is ready for release. No drawing should advance without a documented approval. 

Release marks the drawings as the current, controlled version authorized for use in production, construction, or procurement. Released drawings should be locked against further editing. Any subsequent change triggers a new revision cycle, not an overwrite. 

Archive is the end-of-life stage for a drawing that has been superseded or is no longer active. Archived drawings should remain accessible for audit and reference purposes but clearly flagged to prevent use in active workflows. 

Tracking a drawing through each stages serves three critical functions:

• Revision control ensures that every change is documented, versioned, and traceable back to who made it and when. 
• Suppression control prevents outdated drawings from being used in production or construction, one of the most common and costly errors in engineering document management. 
• Audit readiness means that when a compliance review or quality audit arrives, the complete history of every document is already organized and accessible, not something your team has to reconstruct under pressure.

ImageSite and EngineBox make version control seamless. When a drawing is added to a project/ folder, it becomes version 1. Users (with the proper permissions) can check-out the file to use it in a CAD authoring software. As a user checks-in the drawing, both versions live in the same spot. 

When viewing the file in our EDMS, the viewer defaults to the newest version. The version label at the bottom shows which version you’re viewing, while doubling as a dropdown used to view all previous versions of a drawing. 

Using the security and access controls, user roles can control access to drawings at different stages in their lifecycle. Administrators can manually set document statuses; however, status can be automated using Workflow+. 

Automations route documents for approval and archiving. Relevant users are notified through conventional emails or internal notifications on our platform’s dashboard.

Which File Formats Does Our EDMS Support?

eQuorum’s ImageSite and EngineBox can store and manage any electronic file type. The integrated high-performance viewer allows users to view and markup most raster file types, MS office, Adobe Acrobat, CAD/ vector files, and PostScript file types. 

Any file that can be viewed is supported for markup, collaboration, and server-side printing.

Learn more about how ImageSite and EngineBox handle different file types.

CAD File Management is a Systems Problem

CAD files are more than design artifacts; they’re the operational backbone of every engineering project your organization runs. How they’re stored, shared, accessed, and controlled determines whether your teams are working from accurate information or quietly accumulating the kind of errors that surface at the worst possible moment. 

Format complexity, Xref dependencies, version drift, PDF limitations, remote access friction, shop floor accuracy, and lifecycle control aren’t independent problems. They’re symptoms of the same underlying issue: managing engineering documents without a system built for engineering documents. 

A general-purpose file share, an email thread, or a manually maintained folder structure can’t enforce check-out controls, stream version-accurate drawings to a machinist’s phone, route documents through an approval workflow, or produce an audit trail on demand. An EDMS purpose-built for CAD environments can do all of it – and do it without adding complexity to the workflows your engineers are already running. 

eQuorum’s ImageSite and EngineBox were built specifically for engineering organizations that need more than file storage. Whether your team is managing a handful of projects or thousands of controlled documents across multiple disciplines, the right document management foundation keeps everyone from the design engineer to the shop floor operator working from the same source of truth. 

If your current CAD file sharing workflow relies on any of the workarounds described in this guide, it’s worth taking a closer look at what purpose-built EDMS can do for your organization. 

CAD File Sharing FAQs

How do I open a DWG file without AutoCAD?

There are several ways to open a DWG file without an AutoCAD license. DWG TrueView is Autodesk's free desktop viewer for Windows that opens DWG and DXF files natively. Autodesk Viewer offers browser-based viewing across any operating system at no cost with a free Autodesk account. 

For teams managing multiple drawings across a project, an EDMS like eQuorum's ImageSite or EngineBox embeds DWG viewing directly into the document management system — no separate software or local file installation required.

Can I view CAD files on a Mac or Chromebook?

Yes. Browser-based viewers like Autodesk Viewer work across operating systems, making them a practical option for Mac and Chromebook users who don't have access to Windows-native desktop tools. 

A browser-based EDMS is the most reliable solution for organizations with mixed device environments — users get consistent, version-controlled access to CAD drawings regardless of what hardware they're on.

How do I convert a DWG to PDF?

In AutoCAD, go to Application > Export > PDF, or open the Plot dialog with Ctrl+P and select DWG to PDF under Printer/Plotter. Most CAD authoring tools include a similar export or plot function. 

Keep in mind that a manually exported PDF is a static snapshot — it won't update when the source file changes. eQuorum's EDMS streams a PDF directly from the native CAD file, so the version stakeholders see is always current without any manual re-export.

How can I share CAD files securely with vendors or contractors?

Email and shared drives are the most common approaches, but both create version control and security risks once a file leaves your environment. A more secure method is granting external stakeholders permissioned access through a browser-based EDMS. 

Users see what they need — the current, approved drawing — without the native file ever leaving the system. Every access event is logged, and permissions can be revoked instantly when a project phase ends or a vendor relationship changes.

What software supports both DWG and DXF formats?

Most CAD authoring tools and viewers support both formats. Autodesk products handle DWG and DXF natively, and both formats are supported by Autodesk Viewer and DWG TrueView. 

eQuorum's ImageSite and EngineBox support DWG, DXF, DGN, and a wide range of other CAD and raster formats within a single document management environment — eliminating the need for format-specific tools across your team.

How do I give shop floor workers access to the latest drawings?

The most reliable method is QR-code-based access tied directly to the controlled document in your EDMS. eQuorum's ScanNTap module does exactly this — shop floor staff scan a code with any mobile device and the current, approved drawing opens in their browser. No app, no login complexity, no risk of someone working from a printed copy that's been superseded. Access can be set to read-only to prevent any modifications to the source file.

What is CAD stage progression and how do I track it?

CAD stage progression refers to the defined lifecycle a drawing moves through from initial design to final archive: Design, Review, Approval, Release, and Archive. 

Tracking this progression ensures drawings are only used at the appropriate stage, every change is versioned and traceable, and your organization can demonstrate compliance during audits. 

In eQuorum's ImageSite and EngineBox, document statuses can be set manually or automated through Workflow+, which routes drawings for approval, notifies relevant stakeholders, and maintains a complete audit trail throughout the document's lifecycle.

What is the difference between a CAD viewer and CAD software?

CAD software — like AutoCAD, MicroStation, or SolidWorks — is a full authoring environment for creating and editing design files. It's powerful, expensive, and requires training to use effectively. 

A CAD viewer is a lightweight tool built for opening, inspecting, and in some cases marking up drawings without editing the underlying geometry. Viewers are the practical solution for project managers, contractors, clients, and other stakeholders who need to review drawings regularly but don't need — or shouldn't have — edit access to the source files.